Mendogia bambusina Racib., Parasit. Alg. Pilze Java’s (Jakarta) 3: 31 (1900)

Index Fungorum number: IF201717

Epiphytic on living bamboo culms. Sexual morph: Ascostromata 0.98–1.85 mm diam., scattered, solitary to gregarious, superficial on host surface, black, flattened, circular to round, hemisphaerical or shield-shape, rugulose, sunken near the edge, easily removed from the host, loculate, glabrous, walls rough, carbonaceous at the outer surface, with centre sterile region and fertile region located near the margin. Fertile region locule-like, 100–210 μm high, 260–420 μm diam. in vertical section, forming as circular ring near the edge of ascostroma, immersed in ascostroma, raised, subglobose to hemisphaerical, with asci separated by paraphysoid-like filaments, discharging asci and ascospores via cracking of the outer walls, with slit-like opening. Peridium 15–60 μm wide, thick-walled, of unequal thickness, thick at the rim, slightly thin at the base, composed of two layers, of dark brown to black cells, outer layers comprising thick, black, melanized cells, carbonaceous, arranged in a textura angularis, inner layers comprising thick, brown to dark brown, pseudoparenchymatous cells, arranged in textura angularis. Hamathecium composed of dense, 1.5–4 μm wide, paraphysoid-like filaments, septate, constricted at the septum, anastomosing among the asci. Asci arranged in type II, (55–)60– 75(−80)(−90) × (17–)18–22(−25) μm (x = 71.6 × 20.5 μm, n = 25), 8-spored, bitunicate, fissitunicate, cylindric-clavate to clavate, short pedicellate, apically rounded with well-developed ocular chamber, thickened at the apex. Ascospores (13.5–)17–20(−25) × (5–)6–8 μm (x = 19.4 × 6.7 μm, n = 30), overlapping, uni- to tri-seriate, hyaline, ellipsoidal to clavate, muriform, with 3–5 transverse septa and 1–2 longitudinal septa, constricted at the septum, smooth-walled. Asexual morph: Undetermined.

Material examined: INDONESIA, Jawa Barat (West) District, Java, Buitenzorg, on bamboo, 1907, G. v. Höhnel (S, F48345).

Notes: Mendogia bambusina differs from other Mendogia species in having asci arranged in a fertile region lying as concentric rings near the edge of ascostroma, with muriform ascospores, having 4–5 transverse septa and 1–2 longitudinal septa.

FIG.  Mendogia bambusina (S F48345). a Herbarium materials; b Black ascostromata on bamboo host; c Section of ascostroma; d, e Peridium; f Asci separated by paraphysoid-like filaments; g–i Asci; j–o Ascospores (m–o: Ascospores stained in cotton blue); Scale bars: c = 100 μm, d–i = 20 μm, j–o=5 μm